The PB-503C is the PB-503 mounted in a heavy-duty, portable, aluminum carrying case. The PB-503 is our time-tested workhorse designed for all levels of electronics instruction and prototyping. Utilizing the PB-503, students can create and implement their own circuits onto the breadboard, which is removable for multiple student usage in lab settings. For both series and parallel circuits, the PB-503 can also handle much more sophisticated multi-stage microcomputer circuits.